Durable press finish for wool/cellulosic fabrics (melamine/dihydroxy-imidazolidinone resins)

ABSTRACT

A METHOD FOR IMPARTING DURABLE PRESS PROPERTIES TO TEXTILE FABRICS CONTAINING A PROTEIN FIBER SUCH AS WOOL AND CELLULOSE FIBERS COMPRISING IMPREGNATING SAID FABRIC WITH A SINGLE BATH COMPRISING A RESIN FORMING MATERIAL WHICH MAY COMPRISE A COMBINATION OF MATERIAL, I.E., A POLYMETHYLO! MELAMINE AND 1,3-DIALKYLOL-4,5-DIHYDROXY2-IMIDAZOLIDINONE AND A DELAYED ACTION CATALYST, DRYING AND SUBSEQUENTLY CURING SAID METHYLOL MELAMINE AND 1,3-DIALKYLOL-4.5-DIHYDROXY-2-IMIDAZOLIDINONE ON SAID FABRIC, THE COMPOSITION FOR THE METHOD AND THE TREATED FABRIC.

3,627,556 DURABLE PRESS FINISH FOR WOOL/CELLU- LOSIC FABRICS (MELAMINE/DIHYDROXY- IMIDAZOLIDIN ONE RESINS) Philip B. Roth, Bridgewater Township, Somerset County, N.J., and Herbert Jack Leavitt, Millbrae, Calif.; said Roth assignor to Koratron Company, Incorporated, San Francisco, Calif.

No Drawing. Filed July 29, 1968, Ser. No. 748,174

Int. Cl. D06m /54, 15/70 US. Cl. 117--10 Claims ABSTRACT OF THE DISCLOSURE A method for imparting durable press prop- This invention relates to durable press finishes. More particularly, it relates to a method for imparting durable press properties to textile materials containing protein fiber such as wool or mohair and cellulosic fibers by applying an aqueous solution of a resin forming material such as a combination of methylol melamine and 1,3-dialkylol-4,5 dihydroxy-Z-imidazolidinone and curing the finish in the presence of a curing catalyst. Still more particularly the invention relates to the curing of the resin finish by a deferred curing operation. Furthermore, it also relates to the textile materials thus treated.

Durable press finishes for cellulosic textile materials, particularly for blends of cellulosic textile synthetic fibers such as Dacron and nylon, are well known. The deferred curing technology of such finishes is also well known. Large amounts of fabric are treated with the finishes and dried. Manufacturers then cut and sew the fabric into garments and the garments are pressed to impart creases where creases are desired and smoothness and shape where creases are not desired. Finished garments are then heated in an oven, or otherwise, to effect the curing of the finish on the completed garment. The Koret patent, US. 2,974,432, describes the above process, now known as the Koratron process.

The preferred finish for use in the Koratron process contains 1,3-dimethylol-4,5-dihydroxy-2-imidazolidinone, commonly called dimethylol-dihydroxy-ethyleneurea. A curing catalyst, such as zinc nitrate, is also normally present in the finish. The finish, when applied by a deferred cure process, imparts excellent durable press properties to cellulosic fibers, and blends of cellulosic and synthetic fibers.

Satisfactory durable press properties are not obtained when the above finish is applied by the deferred curing method to blends of wool and cellulosic fibers. Although good durable press properties can be imparted by applying two textile finishes in separate operations to blends of wool and cellulosic fibers, such operations are obviously time-consuming and undesirable.

The object of this invention is to provide a single bath, durable press finish for textile materials containing a protein fiber such as wool or mohair and cellulosic fibers, i.e., a finish suitable for the deferred curing method. Also, the finish should not only provide crease retention where creases are desired, and smoothness of fabric where creases and wrinkles are not desired, but these qualities nited States Patent 0 must persist after laundering. Furthermore, the finish should provide resistance to shrinkage due to laundering, and the hand of the fabric should be satisfactory. Lastly, the treated and dried fabric must be stable to storage before curing. It has now been discovered that the above objects can be attained by (1) applying, as a single bath, an aqueous solution which may contain two types of aminoplast resin to a textile fabric containing wool and cellulosic fibers, (2) drying the treated fabric of a temperature below the curing temperature, and (3) subjecting the dried fabric to a curing operation, either conventional or deferred.

Fabric to be treated by the process of this invention contains at least 40%, preferably at least 45%, of wool fibers and at least 20%, preferably at least 25 of cellulosic fibers. Cellulosic fibers include cotton and regenerated cellulose, i.e., rayon, particularly viscose rayon. Other fibers may be present, including the synthetic fibers such as the polyamide (nylon) fibers, polyester (Dacron) fibers and polyacrylic (Orlon and Creslan) fibers.

The two types of aminoplast resins or reactants (i.e., the resin or reactant precondensates) are (1) methylol melamines containing at least two methylol groups and (2) 1,3-dialkloyl-4,5-dihydroxy-2-imidazolidinone, wherein said alkylol group has from 1 to 3 carbon atoms, preferably 1,3-dimethylol-4,S-dihydroxy 2 imidazolidinone. Both types of aminoplasts are well known and find extensive use on cellulosic fibers. The methylol melamines also find use on wool to reduce shrinkage and felting.

Among the melamine-based resins which may be used are methylated trimethylol melamine, methylated pentamethylol melamine, and methylated hexamethylol melamine, including hexa(methoxymethyl)melamine. The preferred resin is a methylated trimethylol melamine, having at least 50% of the methylol groups methylated. By trimethylolmelamine, it will be understood that the average number of methylol groups is from about 2.8 to 3.2. Combinations of 2 or more melamine-based resins may be used.

The two types of aminoplast resins are compatible in aqueous solutions. The wool/cellulosic fabric is impregnated with the resin solution by any of the well-known procedures, including dipping, padding, spraying, etc.

The amount of melamine-based resin applied on the fabric is between 3% and 25% based on the weight of the fabric (O.W.F.), preferably between 4% and 18% O.W.F. The amount of imidazolidinone-based resin ap plied is between 2% and 18%, preferably 3.5% and 12% O.W.F. The total aminoplast resin should be at least 8% O.W.F., preferably at least 12% O.W.F.

Since the treated wool/cellulosic fabrics will normally pick up between 70% and of their weight of treating solution, the amount of melamine-based resin in the solution will be between 4% and 20% of the solution, preferably between 6% and 15%. The amount of imidazolidinone-based resin will be between 3% and 15% preferably between 5% and 10%.

The catalyst utilized may be free acid. acid salts, alkanolamine salts, metal salts and the like. The concentration of catalyst employed may range from about 0.1 to about 25% or higher, based on the weight of the resin solids, depending upon the particular catalyst type employed. Thus, for example, from between about 0.1 and about 10% of a free acid such as phosphoric, tartaric, oxalic or the like, may be employed, while in the case of ammonium chloride, amounts of from between 0.5 and about 10% are used. In the case of amine salts, including alkanolamine salts, such as diethanolamine hydrochloride, from about 1.0 to about 10% are most useful, while the respect to salts such as magnesium chloride, zinc chloride, zinc nitrate, and aluminum chloride,

3 amounts of between about 5 and 25%, preferably 8 to 15%, have been successfully employed. In all instances, the concentration of the catalyst is based on the Weight of the resin solids employed.

After impregnation with the resin and catalyst solution, the fabric is dried at a temperature below 250 F., preferably at a temperature between 200 F. and 230 F. At the preferred range, between 1 and 10 minutes will normally be required.

Although the treated and dried fabric can be cured immediately, or after storage, in the fiat state, full benefit of this invention is obtained by cutting and sewing the treated, dried fabric into garments, which are pressed and shaped as desired. The garments are then heated, as in an oven, for a sufficient length of time, to effect a cure of the finish on the fabric of the garment. The garment thus acquires a durable press, with shape, desired creases and smoothness where each is desired.

The recommended curing temperature is between 290 F. and 350 F., preferably between 300 F. and 340 F. The curing time will range from A. to 30 minutes, depending on the temperature used.

If desired, other textile treating agents and additives may be present in the resin/catalyst impregnating solution. These additives include softeners, water repellents, surface active agents, etc.

In the following examples, the precentages are by weight. The retention of creases was evaluated by the AATCC Tentative Test Method 88C-1964T. The smoothness of the fabric, i.e., the minimum care appearance, was evaluated by AATCC Tentative Test Method 88A 1964T, employing overhead lighting. The fabrics were rated on a scale of 1-5, 5 representing the smoothest appearance and best retention of the original condition and 1 representing the poorest appearance and poorest retention of the original condition.

The following examples are given to illustrate the invention and are not intended to be limitative.

EXAMPLE 1 A 50/ 50 wool/rayon fabric was immersed in an aqueous solution containing 11.3% of partially methylated trimethylol melamine (Resin A), 7.0% of 1,3-dimethyl- 01-4,5-dihydroxy-2-imidazodinone (Resin B), 1.8% of zinc nitrate (Catalyst A), 1.1% of stearoylethyl dihydroxypropyl dimethyl ammonium chloride (Softener A) and 0.25% of ethylene oxide aciduct of nonylphenol (Surfactant A). The fabric was then passed through suitable rolls, as in a padder, so that the fabric had a 95% wet pickup. The fabric was dried at 210 F. for minutes. The treated fabric contained 10.7% of melamine resin and 6.7% of imidazolidinone resin.

A portion of the dried fabric was pressed to impart a crease and then cured by heating in an oven at 315 F. for 10 minutes. The cured fabric was washed in a home-style, automatic washing machine using water at 140 F. and a detergent. The washed fabric was tumble dried after each washing. The shrinkage of the pressed and cured fabric was measured before and after 5 washing cycles. The shrinkage of the untreated fabric was also measured. The results are shown in Table I as the percent shrinkage of warp (W) and fill (F).

The cured fabric exhibits excellent crease retention and excellent minimum care appearance after the washings.

A portion of the dried, but uncured, fabric was stored for 7 weeks. Samples of this fabric were pressed to form EXAMPLE 2 Three pad baths were prepared of the following composition:

TABLE II Pad bath 1 Pad bath 2 Pad bath 3 Resin A, percent 11. 3 8. 0 6. 0 Resin B, percent 7.1 7. 1 7. 1 Catalyst A. percent 1. 8 1. 4 1. 2 Softener A. percent 1.1 1.1 1.1 Surfactant A, percent- 0. 25 l). 25 0. 2

The pad baths were applied to 50/ 40/ 10 wool/rayon/ nylon fabric by a standard padding procedure obtaining a wet pick-up of The fabrics were dried at 225 F. for 4 minutes. The fabrics contained 9.0%, 6.4% and 4.8% of melamine resin and 5.7% of imidazolidinone resin.

Swatches of the dried fabric were creased by pressing for 10 minutes at 310 F. The swatches were then heated in an oven at 340 F. for 10 minutes. The swatches were washed five times in a home-style washing machine using water at 140 F., tumble drying after each washing cycle. The shrinkage of the washed fabric, including a swatch of washed, untreated fabric, is shown in Table III as percent shrinkage of warp and fill. Crease retention and minimum care appearance of the washed fabrics are also shown in the table. Fabrics 1, 2 and 3 correspond with pad baths 1, 2 and 3, respectively.

TABLE III Minimum care appearance Shrinkage F percent Crease percent Untreated EXAMPLE 3 A 50/50 wool/rayon fabric was immersed in an aqueous solution containing 8.4% of resin A, 5.3% of resin B, 1.05% of mixed siloxanes (water repellent A) and 1.65% of magnesium chloride (Catalyst B). The fabric was squeezed through rollers to impart a wet pick-up and the fabric was dried at 225 F. for 3.0 minutes. The fabric contained 8.8 melamine resin and 5.6% imidazolidinone resin.

Swatches of the dried fabric were creased by pressing at 325 F. for 15 seconds, (1) immediately after drying, (2) after 14 days at F., and (3) after 7 weeks at room temperature. The swatches were then heated in an oven at 350 F. for 10 minutes.

All of the fabrics demonstrated excellent crease re tention after five washings in an automatic washing machine using water at 120 F.

EXAMPLE 4 A 50/50 wool/rayon fabric was immersed in an aqueous solution containing 8.4% of dimethylol melamine, 5.3% of Resin B, 1.0% of Water Repellent A, 3.1% of a textile softener (mixed cationic and anionic long-chain derivatives), 1.65% of Catalyst B and 0.25% of Surfactant A. The fabric was squeezed through rollers to impart a 95% wet pick-up. The fabric was dried at 225 F.

for 4 minutes. The fabric contained 8.0% of melamine resin and 5.0% of imidazolidinone resin.

A swatch of the dried fabric was pressed at 310 F. for 15 seconds and then heated in an oven at 317 F. for minutes.

The fabric demonstrated excellent crease retention after five washings in an automatic washing machine using water at 140 F.

While certain specific embodiments and preferred modes of practice of the invention have been described, it will be understood that this is solely for illustration, and that various changes and modifications of the invention may be made without departing from the spirit of the disclosure or the scope of the appended claims.

We claim:

1. A method for imparting durable press properties to textile fabrics containing protein and cellulose fibers comprising impregnating said fabric with an aqueous medium containing a polymethylol melamine, 1,3-dialkylol-4,S-dihydroxy-Z-imidazolidinone and a delayed action catalyst, said melamine being from about 3 to about 25 and said imidazolidinone being from about 2 to about 18% based on the weight of said fabric, and sub sequently drying and curing said impregnated fabric.

2. The method of claim 1 wherein said catalyst is a zinc salt.

3. The method of claim 2 wherein said catalyst is zinc nitrate.

4. The method of claim 1 wherein said melamine and imidazolidinone are applied in a combined weight between about 8% and 30% on the weight of fabric.

5. The method of claim 1 wherein said polymethylolmelamine is a methylated trimethylolmelamine having at least 50% of the methylol groups methylated.

6. The method of claim 1 wherein said textile fabric contains at least 40% wool and at least 20% cellulose.

7. The method of claim 1 wherein said textile fabric contains synthetic fibers.

8. A textile material having crease resistant properties as produced by the method of claim 1.

9. The method of claim 1 wherein said imidazolidinone is 1,3-dimethylol-4,5-dihydroxy-2-imidazo1idinone.

10. The method of claim 1 in which said impregnated fabric is dried at a temperature below about 250 F.

11. The method of claim 1 in which said impregnated fabric is cured at a temperature within the range of about 290 to about 350 F. for approximately to about 30 minutes.

12. The method of claim 7 in which said blend of fibers contains at least about 40% by weight protein fibers and at least about 20% by weight cellulose fibers.

13. The method of claim 10 in which said impregnated 6 fabric is dried at a temperature within the range of about 200 to about 230 F. for approximately 1 to about 10 minutes.

14. A method of forming permanently creased garments comprising the steps of impregnating a fabric comprising a blend of cellulose and protein fibers with a single liquid formulation comprising an aqueous medium containing a resin forming material comprising polymethylol melamine and 1,3-dia1kylo1-4,5-dihydroxy-2- imidazolidinone and a catalyst, said melamine being from about 3 to about 25% and said imidazolidinone being from about 2 to about 18% based on the weight of said fabric with the total weight of the resin forming material being at least about 8% based on the weight of said fabric, drying and forming said impregnated fabric into a garment and imparting at least one crease thereto, and subsequently curing said creased garment to impart to said garment the property of crease retention.

15. The method of claim 14 wherein said imidazolidinone is 1,3-dimethylol-4,S-dihydroxy-Z-imidazolidinone.

16. A permanently creased garment as produced by the method of claim 14.

17. The method of claim 14 in which said blend of fibers contains at least about 40% by weight protein fibers and at least about 20% by weight cellulose fibers.

18. The method of claim 14 in which said impregnated fabric is cured at a temperature within the range of about 290 to about 350 F. for approximately to about 30 minutes.

19. A textile material containing wool and cellulose fibers and impregnated with about 3 to about 25% based on the weight of said material of a polymethylol melamine, about 2 to about 18% based on the weight of said material of 1,3 dialkylol4,5-dihydroxy-2-imidazolidinone and a delayed action catalyst.

20. The textile material of claim 19 wherein said imidazolidinone is l,3-dimethylol-4,S-dihydroxy-Z-imidazolidinone.

References Cited UNITED STATES PATENTS 2,731,364 1/-1956 Reibnitz et al. 117139.4 2,974,432 3/1961 Warnock et al. 1l7139.4 3,079,279 2/1963 Van Loo 117139.4 3,116,967 1/1964 Goldstein et al. 117139.4 X

WILLIAM D. MARTIN, Primary Examiner T. G. DAVIS, Assistant Examiner US. Cl. X.R. 

